Oval patellar prosthesis having dome shaped contact surface for trochlear groove

摘要

An improved knee prosthesis disclosed that includes a patella for positioning in a trochlear groove formed by two condyles of a femoral component. The novel patella of the disclosure has an elliptical outer periphery and presents an articulating surface to the femoral component for sliding engagement with a trochlear groove formed between the condyles of the femoral component. A side opposite the articulating surface has extending therefrom three posts which enhance the attachment of the patella prosthesis to the patella bone. In one embodiment of the invention an undercut area which is cut into the bone contacting surface of the prosthesis presents an overhang or undercut to the bone in order to enhance cement fixation. The overhang is formed by an outer defining wall which is positioned at an angle to a bottom surface of the recessed overhang area of between 50 and 75 DEG .